Over the last couple of years I converted my compact disc collection to digital files. This allows me to enjoy the music in whatever venue I happen to occupy: car, living room, basement lair (aka the "country bunker"), MARC train, interplanetary shuttle or molecular transport. No need to lug the discs and player with me and through the magic of miniaturization I simply plug a AudioQuest Dragonfly Red DAC (digital-analog converter) into the lightning connector on an iPad. Said iPad reads the files from a terabyte-sized storage device and to the headphones via the DAC which happens to include a headphone amp.
Apple has presented a bit of a hurdle in connecting high capacity storage to their portable devices. You cannot just plug something in. In this case a tiny RAVPower FileHub connected to a 1TB external storage device is wirelessly sending files via a built-in wi-fi. Does one terabyte seem like overkill? Au contraire, so far my music collection consumes over 250GB. To date this does not include video but someday ...
Once down the path of hosting a file-based music collection, purely digital distribution attracted my oft fleeting attention. These days my favorite purveyor is HDTracks who has become one of if not the largest seller of digital music files. My travel system is optimized for 24 bit/96kHz and the remastered version of the Beatles "Sgt. Pepper's Lonely Hearts Club" album presents an incredibly clear sound at this bit depth and resolution. At this point let me say that not all recordings will present in an improved fashion in uncompressed format(s). Something that was heavily manipulated, compressed during recording, mixing or mastering, or otherwise adulterated may not offer a perceptible sonic improvement at 24 bit/96kHz (or for that matter anything over the lowly CD's 16 bit/44.1kHz) and occasionally one may even prefer the MP3 rip. YMMV but modern recordings and remasters from quality source material including HDTracks cofounder David Chesky's Binaural+ Series do quite well in the upper stratosphere of lossless file containment.
Of course after I had "ripped" all the discs to digital files using MP3 encoding, the benefits of a lossless format became obvious as my audio playback chain improved. Nothing wrong with MP3 when listening in a noisy environment but with KEF headphones running through the Dragonfly, baby wants, even needs lossless compression. So a second pass was made of digitizing the CDs using the dBPoweramp CD Ripper and saving to the Apple ALAC file format. In the no-good-deed-goes-unpunished department, I now wish I had used the open-source FLAC format but hey, who's to say I won't re-re-rip all those disc or simply convert from ALAC to FLAC using the dBPoweramp Music Converter?
[Quality Update: added an Audioquest "Jitterbug" USB data & power noise filter which purports to "reduce the noise and ringing that plague both the data and power lines of USB ports." I like the sound but have not yet done extensive A/B tests. Stay tuned ...].
[Added a 2nd Jitterbug to the portable system so now they are on the file store and DAC. Subtle improvements but definitely there for at least some of the recordings I listen to. Sampled the remastered Parton/Harris/Ronstadt "Trio II" recording and Tom Cunningham Orchestra "Swingin' and Singin'" to positive effect. The bass is more open, highs are clearer and separation between multiple vocalists and instruments is enhanced.]
[Android Phone Update -- added USB Audio Player PRO to the Moto G6. This is now working with the Dragonfly Red and micro-SD storage (200GB) and boosts audio levels by correctly sensing the Dragonfly volume levels. A test sending to the car system via bluetooth was also successful.]